The study of the molecular mechanisms which control the cell cycle has made it possible to demonstrate the role of the cdk's thus defined: these cdk's are essential regulators of the cell division cycle; cdk's are proteins which consist of at least two subunits, a catalytic subunit (of which cdc2 is the prototype) and a regulatory subunit each of which is involved in a phase of the cell cycle.
Numerous documents in the literature describe the existence and the role of cdk's and, by way of example, there may be mentioned in particular the document WO 97/20842.
Several kinase inhibitors have been described, such as butyrolactone, flavopiridol and 2(2-hydroxyethylamino)-6-benzylamino-9-methylpurine called olomoucine).
Such cdk activating protein kinases are in particular those of pathogenic fungi which cause infectious diseases in the human body.
As pathogenic fungi, in the context of the present invention, there may be mentioned Candida albicans but for example and equally well: Candida stellatoidea, Candida tropicalis, Candida parapsilosis, Candida krusei, Candida pseudotro-picalis, Candida quillermondii, Candida glabrata, Candida lusianiae or Candida rugosa or alternatively mycetes of the Saccharomyces cerevisiae type, of the Aspergillus or Cryptococcus type and in particular, for example, Aspergillus fumigatus, Coccidioides immitis, Cryptococcus neoformans, Histoplasma capsulatum, Blastomyces dermatitidis, Paracoc-cidioides brasiliens and Sporothrix schenckii or alternatively mycetes of the phycomycetes or eumycetes classes, in particular the basidiomycetes, ascomycetes, mehiascomycetales (yeast) and plectascales, and gymnascales (fungus of the skin and of the hair) subclasses, or of the hyphomycetes class, in particular the conidiosporales and thallosporales subclasses among which are the following species: mucor, rhizopus, coccidioides, paracoccidioides (blastomyces, brasiliensis), endomyces (blastomyces), aspergillus, menicilium (scopulari-opsis), trichophyton, epidermophton, microsporon, piedraia, hormodendron, phialophora, sporotrichon, cryptococcus, candida, geotrichum, trichosporon or toropsulosis, pityriasis Versicolor or Erythrasma. Among such pathogenic fungi, there may be mentioned most particularly Candida albicans. It can be noted that the first kinases activating fungal cdk's were identified in Saccharomyces cerevisiae and Schizosaccharomyces pombe. The activation of cdk's requires both the attachment of a cyclin molecule and the cdk phosphorylation on a conserved threonine residue located in a region called “T loop”. It has been shown that this phosphorylation is carried out by a kinase called “cdk activating kinase” or “CAK”. By way of additional information on these “CAK's”, there may be mentioned the contents of the documents whose references are as follows:                'Solomon, Trends Biochem. Sci. 19, 496–500 (1994)        'Buck et al, EMBO J., 14(24), 6173–83 (1995)        'Damagnez et al, EMBO J., 14(24), 6164–72 (1995).In the yeast Saccharomyces cerevisiae, a kinase has been identified which is responsible for the CAK activity, which has been called CIV1.By way of additional information on these “CIV1's”, there may be mentioned the contents of the documents whose references are as follows:        Thuret et al, Cell, 86(4), 1996)        Kaldis et al, Cell, 86(4), 553–564 (1996),        Espinosa et al, Science, 273(5282), 1714–1717 (1996).Such a CAK activity, as defined above, which is essential for survival and cell division, has been found and identified in pathogenic fungi such as, in particular, Candida albicans: the sequence of the gene encoding this CIV1 protein in Candida albicans called CaCIV1 and the protein CaCIV1 have been identified. Such a sequence and its protein are clearly defined in French Patent Application No. 9710287.        